I talked to Bill at Acme a while back and he had recommended a prop that would have supposedly gained +4 mph on the top end for a MCX/Slot 197. Unfortunately, I can not find that email now, but I want to say it was a #541 or 542.

If a prop could gain that much top end on a 197, it would be pretty impressive. I ended up not going that route as I already had 2 OJ's, we don't 'foot that much any more and I thought the 4 glad OJ might give a softer skier pull.